U.S. patent application number 13/239222 was filed with the patent office on 2012-01-12 for wireless intelligent switch engine.
This patent application is currently assigned to SONY ELECTRONICS, INC.. Invention is credited to Eric Yam.
Application Number | 20120008562 13/239222 |
Document ID | / |
Family ID | 32328910 |
Filed Date | 2012-01-12 |
United States Patent
Application |
20120008562 |
Kind Code |
A1 |
Yam; Eric |
January 12, 2012 |
WIRELESS INTELLIGENT SWITCH ENGINE
Abstract
A wireless intelligent switch engine (WISE) is described. The
wireless intelligent switch engine provides for automatic switching
between different physical wireless interfaces in mobile devices
while roaming to maintain a wireless network connection. WISE
functions as a bridge between a mobile device and multiple wireless
network interfaces to provide automatic and seamless switching
among networks while roaming. The mobile device sees WISE as a LAN
interface and communicates with WISE using the TCP/IP protocol
stack, thus providing a PPP-less configuration that uses the TCP/IP
protocol stack regardless of the wireless interface.
Inventors: |
Yam; Eric; (San Diego,
CA) |
Assignee: |
SONY ELECTRONICS, INC.
PARK RIDGE
NJ
SONY CORPORATION
TOKYO
|
Family ID: |
32328910 |
Appl. No.: |
13/239222 |
Filed: |
September 21, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12717404 |
Mar 4, 2010 |
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13239222 |
|
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10387362 |
Mar 11, 2003 |
7702357 |
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12717404 |
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60429480 |
Nov 26, 2002 |
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Current U.S.
Class: |
370/328 |
Current CPC
Class: |
H04W 36/14 20130101;
H04W 48/18 20130101; H04W 88/06 20130101 |
Class at
Publication: |
370/328 |
International
Class: |
H04W 4/00 20090101
H04W004/00 |
Claims
1-72. (canceled)
73. An apparatus for switching between network interfaces,
comprising: a switch engine configured for operating at the data
link layer of a protocol stack for a given interconnection model
configured for operation with multiple network interfaces; said
switch engine configured to automatically select and establish a
network connection session for a mobile device through an active
interface, within the multiple network interfaces; and a bridge
formed by said switch engine between at least two wireless network
interfaces of different types within said multiple network
interfaces without closing and restarting the network connection
session which has been established.
74. An apparatus as recited in claim 73: wherein said protocol
stack comprises the Open Systems Interconnection (OSI) reference
model for a TCP/IP protocol; and wherein said switch engine is
configured for operating within the data link layer of the of said
protocol stack.
75. An apparatus as recited in claim 73, wherein said switch engine
communicates with said wireless interfaces through a priority field
within a packet header using tag control information.
76. An apparatus as recited in claim 75, wherein the priority field
is used to select a wireless interface based on a priority criteria
selected from the group of fields consisting essentially of frame
quality, receive frame CRC error, and signal strength.
77. An apparatus as recited in claim 73, wherein said switch engine
performs quality of service priority queuing in determining
selection of the network interface within the multiple network
interfaces.
78. An apparatus as recited in claim 77, wherein said quality of
service priority queuing is performed based priority, bandwidth,
signal strength, frame quality, frame error rate (FER), receive
frame CRC error, or combinations thereof.
79. An apparatus as recited in claim 73, wherein said switch engine
utilizes bandwidth tagging with a tag control information field to
control which network interface is selected.
80. An apparatus as recited in claim 79, wherein said tag control
information field maps to a switching/packet management table as a
switching criteria.
81. An apparatus as recited in claim 73, further comprising power
management within said switch engine which shuts down, or places
into standby mode, network interfaces, within the multiple
interface devices, which it determines are not the active interface
device to reduce power consumption.
82. An apparatus for multiple-network communications, comprising: a
mobile device configured for establishing a network connection
session for communicating with different types of wireless networks
through multiple network interfaces; and a switch engine,
configured for operation within a data link layer of a protocol
stack of said mobile device, for automatically bridging between
said mobile device and at least one of said multiple network
interfaces without closing and restarting the network connection
session.
83. An apparatus as recited in claim 82, wherein said bridging is
performed in response to said mobile device roaming between
different types of wireless networks.
84. An apparatus as recited in claim 83, wherein said protocol
stack comprises the Open Systems Interconnection (OSI) reference
model for a TCP/IP protocol.
85. An apparatus as recited in claim 82, wherein said switch engine
is configured to reduce power consumption in response to shutting
down, or to placing into standby mode, wireless network interfaces
which are not being utilized.
86. An apparatus as recited in claim 82, wherein said switch engine
is configured for quality of service priority queuing when
determining selection of a network interface, within the multiple
network interfaces, as the active network interface.
87. An apparatus as recited in claim 86, wherein said quality of
service priority queuing is performed based on priority, bandwidth,
signal strength, frame quality, frame error rate (FER), receive
frame CRC error, or combinations thereof.
88. An apparatus as recited in claim 82, wherein said switch engine
utilizes bandwidth tagging with a tag control information field to
control which network interface is selected.
89. A method of mobile device communication when roaming across
multiple networks, comprising: selecting a network interface for a
network connection session, from multiple network interfaces
available to a mobile device, when roaming across multiple
networks; and bridging between the mobile device and a network
interface of said multiple network interfaces within the protocol
stack of the mobile device, and automatically switching between
network interfaces, without closing and restarting the network
connection session, as the mobile device roams between multiple
networks.
90. A method as recited in claim 89, wherein said bridging is
performed within a data link layer of a protocol stack.
91. A method as recited in claim 90, wherein said protocol stack
comprises the Open Systems Interconnection (OSI) reference model
for a TCP/IP protocol.
92. A method as recited in claim 89, further comprising managing
power consumption by identifying which network interfaces are not
active, and shutting down, or placing into standby, network
interfaces that are not being utilized.
93. A method as recited in claim 89, wherein said selecting a
network interface for a network connection session is performed in
response to determining frame quality and using tag control
information to identify the network interface.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 12/717,404 filed on Mar. 4, 2010, incorporated
herein by reference in its entirety, which is a is a continuation
of U.S. patent application Ser. No. 10/387,362 filed on Mar. 11,
2003, now U.S. Pat. No. 7,702,357, incorporated herein by reference
in its entirety, which is a nonprovisional of U.S. provisional
patent application Ser. No. 60/429,480 filed on Nov. 26, 2002,
incorporated herein by reference in its entirety. Priority is
claimed to each of the foregoing applications.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not Applicable
NOTICE OF MATERIAL SUBJECT TO COPYRIGHT PROTECTION
[0004] A portion of the material in this patent document is subject
to copyright protection under the copyright laws of the United
States and of other countries. The owner of the copyright rights
has no objection to the facsimile reproduction by anyone of the
patent document or the patent disclosure, as it appears in the
United States Patent and Trademark Office publicly available file
or records, but otherwise reserves all copyright rights whatsoever.
The copyright owner does not hereby waive any of its rights to have
this patent document maintained in secrecy, including without
limitation its rights pursuant to 37 C.F.R. .sctn.1.14.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] This invention pertains generally to wireless networking,
and more particularly to an apparatus and method that provides for
automatic switching between different network interfaces in a
mobile device so that the mobile device can seamlessly roam among
different types of wireless networks.
[0007] 2. Description of Related Art
[0008] In recent years, wireless network interfaces have become
extremely important to the functionality of mobile devices.
Examples of mobile devices that use wireless networking are laptop
computers and personal digital assistants (PDAs). Wireless
connectivity of a mobile device to the Internet or to an intranet
can increase mobility, convenience and productivity, but there are
certain limitations associated with that connectivity. For example,
the widely used IEEE 802.11 (WLAN) wireless networking technology
provides high bandwidth but is limited in geographical coverage. On
the other hand, while cellular technologies such as
CDMA/WDCMA/GSM/GPRS (WAN) provide much wider (and even global)
geographical coverage, they do so at a much lower bandwidth than
802.11 networking.
[0009] Due to the use of different standards and communications
protocols for wireless networking, in order to achieve true global
coverage it is currently necessary to utilize a combination of
several plug-in or integrated connectivity interfaces and to
manually switch between interfaces while roaming through different
geographical areas or communication sites. For example, a laptop
computer or PDA may have an integrated 802.11b interface and one or
more PCMCIA or CF-card slots for swappable add-on cards. This
allows the user to, for example, select among IEEE 802.11a, IEEE
802.11b, CDMA/WCDMA or GSM/GPRS wireless interface cards. Again,
however, the user experiences a degree of inconvenience since it is
necessary to manually enable, disable or otherwise switch between
the interfaces. For example, the user may have to manually switch
from an 802.11 module to a CDMA/WCDMA or GSM/GPRS module if the
user moves from 802.11 hot spots to cellular networks. With many
operating systems, this also requires the user to close the network
connection session and restart it again using the new wireless
interface.
[0010] Those skilled in the art will appreciate that network
communications typically rely on the Open Systems Interconnection
(OSI) Reference Model in which there are seven communications
layers. Currently, products are available that use OSI Layer 5 to
provide proxy-based session level mobility and OSI Layer 3 with
Mobile IP to provide network level mobility. However, those
products are based on a client/server architecture and roaming
connection changes require interactions of both client and server
components.
[0011] Accordingly, there is a need for seamless roaming capability
to be built-in to mobile devices so that different wireless
interfaces will automatically be selected while roaming without the
need for manual selection and/or restarting the wireless networking
session. The present invention satisfies that need as will herein
be described.
BRIEF SUMMARY OF THE INVENTION
[0012] The present invention provides for the automatic switching
between different physical wireless interfaces in mobile devices
while roaming to maintain a wireless network connection. In general
terms, the invention comprises a wireless intelligent switch engine
(WISE) that functions as a bridge to provide network connection
switching between different interfaces.
[0013] According to an aspect of the invention, network connection
switching is accomplished through the use of Open Systems
Interconnection (OSI) Layer 2 Media Access Control (MAC) bridging
technology. Those skilled in the art will appreciate that OSI
specifies seven layers ranging from the physical layer to the
application layer. Layer 2, the data link layer, defines rules for
sending/receiving data across the physical connection between two
systems.
[0014] In one embodiment, the present invention comprises a Layer 2
bridge that provides network switching between WLAN (802.11) or WAN
(GSM/GPRS/CDMA/WCDMA) using 802.1p/802.1D/802.11 standards to
select the desired wireless interface. In one embodiment, the
bridge resides within the mobile device. In another embodiment, the
bridge is external to the mobile device.
[0015] As can be seen, therefore, an object of the invention is to
allow a mobile device to connect to any wireless network
seamlessly. Further objects and aspects of the invention will be
brought out in the following portions of the specification, wherein
the detailed description is for the purpose of fully disclosing
preferred embodiments of the invention without placing limitations
thereon.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0016] The invention will be more fully understood by reference to
the following drawings which are for illustrative purposes
only:
[0017] FIG. 1 is a schematic diagram of a wireless network
connected to which a mobile device is connected using a wireless
intelligent switch engine according to the present invention.
[0018] FIG. 2 is a diagram showing the relationship of the protocol
stacks in a mobile device and a wireless intelligent switch engine
according to the present invention.
[0019] FIG. 3 is a diagram showing an embodiment of the protocol
stacks used in a wireless intelligent switch engine according to
the present invention.
[0020] FIG. 4 is a diagram showing the Open Systems Interconnection
(OSI) Reference Model with Layer 2 Media Access Control (MAC) used
in the present invention.
[0021] FIG. 5 is a block diagram showing the internal architecture
of the wireless intelligent switch engine of the present
invention.
[0022] FIG. 6 is a block diagram showing the IEEE 802.1D protocol
stack employed in the present invention.
[0023] FIG. 7 is a block diagram showing the IEEE 802.1D internal
organization of the MAC sublayer employed in the present
invention.
[0024] FIG. 8 is a block diagram showing the internal organization
of the relay block of FIG. 7.
[0025] FIG. 9 is a diagram showing the OSI Layer 2 packet header
with IEEE 802.1p tag control employed in the present invention.
[0026] FIG. 10 is a block diagram of a dual mode 802.11a/b
configuration supported by the wireless intelligent switch engine
of the present invention.
[0027] FIG. 11 is a block diagram of a WLAN and WAN configuration
supported by the wireless intelligent switch engine of the present
invention.
[0028] FIG. 12 is a block diagram of a dual WLAN and WAN
configuration supported by the wireless intelligent switch engine
of the present invention.
[0029] FIG. 13 is a block diagram of a WLAN and dual WLAN
configuration supported by the wireless intelligent switch engine
of the present invention.
[0030] FIG. 14 is a schematic diagram illustrating the wireless
intelligent switch engine of the present invention functioning as a
gateway router between a mobile device and wireless network
according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] Referring more specifically to the drawings, for
illustrative purposes the present invention is embodied in the
apparatus generally shown in FIG. 1 through FIG. 14. It will be
appreciated that the apparatus may vary as to configuration and as
to details of the components, and that the method may vary as to
the specific steps and sequence, without departing from the basic
concepts as disclosed herein.
[0032] Referring first to FIG. 1, an example of a wireless network
10 is shown comprising a WAN 12 established by cellular carriers
and a WLAN 14 established by a high speed infrastructure, both of
which are connected either wirelessly or by wired connections to
the Internet 16. A mobile device 18, such as a laptop personal
computer (PC) or personal digital assistant (PDA), is also shown
with capability of communicating with both types of wireless
networks. For seamless roaming between those networks, mobile
device 18 includes a wireless intelligent switch engine (WISE)
according to the present invention as will now be described.
[0033] Preferably, the WISE is completely internal to the mobile
device, but it will be appreciated that the WISE can be implemented
externally as well. WISE communicates with the mobile device and
the wireless interface devices, functioning as a bridge between the
mobile device and the wireless interface devices such that, as the
mobile device roams among the wireless networks, WISE automatically
selects the wireless interface associated with the wireless network
for seamless roaming. This is accomplished, in part, by interfacing
with the mobile device's TCP/IP protocol stack.
[0034] Referring to FIG. 2 and FIG. 3, an example of the
relationship between the protocol stack of the mobile device and
that of the WISE can be seen. As shown, the WISE 20 appears to
mobile device 18 as a network interface card (NIC) 22, thus
providing a PPP-less interface (PPP refers to Point-to-Point
Protocol) is known in the with the mobile device's TCP/IP protocol
stack 24, and bridging mobile device 18 to the required wireless
interface device such as WLAN interface device 26 and WAN interface
device 28 shown. By functioning as a bridge between the mobile
device and its associated wireless network interface devices, WISE
20 allows for seamless roaming among different wireless
networks.
[0035] The invention automatically switches between the wireless
network interface devices using bridging technology that is based
on the Open Systems Interconnection (OSI) Reference Model. As shown
in FIG. 4, OSI specifies a physical layer 30 (Layer 1), a data link
layer 32 (Layer 2), a network layer 34 (Layer 3), a transport layer
36 (Layer 4), a session layer 38 (Layer 5), a presentation layer 40
(Layer 6) and an application layer 42 (Layer 7). The bridging
technology employed by the WISE of the present invention is based
on OSI Layer 2 Media Access Control (MAC) and the IEEE 802.1D
bridging standard.
[0036] Referring now to FIG. 5, an embodiment of the WISE internal
architecture can be seen. In the embodiment shown, WISE 20
comprises a QoS Priority Queuing module 50 (802.1p), a VLAN
Bandwidth Tagging module 52 (802.1Q), a Bridge Switching module 54
(802.1D), a Switching/Packet Management Table 56, and a buffering
module 58 to provide dynamic filtering and switching between a
plurality of wireless interfaces. Referring more particularly to
FIG. 6, the IEEE 802.1D MAC Bridge specifies an architecture and
protocol for the interconnection of networks below the MAC service
boundary. The protocol stack 60 comprises 802.2 Logical Link
Control (LLC) 62 and 802.1D bridging 64 for communication with, for
example, 802.3 (Ethernet) MAC 66 and 802.11 (WLAN) MAC 68 at the
OSI data link layer 32 (Layer 2).
[0037] FIG. 7 and FIG. 8 illustrate an example of the internal
organization of the MAC sublayer based on 802.1D. In FIG. 7, a
first network 70 with LLC 72 and MAC 74 is shown interconnected to
a second network 76 with LLC 78 and MAC 80 by means of an 802.1D
relay module 82 and corresponding bridging MAC 84, 86 for each
network interconnection. The 802.1D bridging standard defines rules
to provide relay capabilities between the two networks. As
illustrated in FIG. 8, relay module 82 comprises three components:
a forwarding process 88, a filtering database 90, and a learning
process 92. The forwarding process 88 forwards received frames of
data that are to be relayed to other bridge ports. The forwarding
process also filters frames on the basis of information contained
in the filter database 90 (e.g., QoS/priority values) and on the
basis of the state of the bridge ports (e.g., on/off based on
signal strength and availability of service). The learning process
92 observes the QoS/priority properties of frames received on each
port and updates the filter database 90 conditionally on the port
state. The filter database 90 holds filtering information and
supports queries by the forwarding process 88 as to whether frames
with given values of the destination MAC address are to be
forwarded (relayed) to a given port.
[0038] WISE 20 then uses the priority field as defined in IEEE
802.1p to select the proper wireless interface. WISE 20 assigns
priorities (0.about.7) based on frame quality; that is, based on
the frame error rate (FER). The FER can be obtained from the
wireless interface itself in most cases or can be computed from the
receive frame CRC error. The priorities assignment can also use
signal strength obtained from the wireless interface in addition to
FER and CRC. Based on this information, the network interface with
higher priority or higher quality and higher bandwidth is selected
as the preferred wireless connection.
[0039] FIG. 9 illustrates the packet header 100 used by WISE 20,
which is an Ethernet OSI Layer 2 packet header with an 802.1p tag
control information field 102. The priority value maps to the
3-bits field 104 of the packet header and the tag control
information field 104 maps to the switching/packet management table
56 (see FIG. 5) as one of the switching criteria for the filter
database 90.
[0040] To enable WISE 20 to select among a plurality of wireless
interfaces, channel identifications are assigned to each of the
wireless interfaces based on the IEEE 802.1Q standard. The VLAN
identifier 106 is shown as part of the tag control information
field 104 in FIG. 9 is defined in the IEEE 802.1Q standard. WISE 20
uses this field to assign network identification or channel numbers
for LAN (interface with the mobile host device), for WLAN, for
CDMA/WCDMA or for GSM/GPRS networks so that WISE 20 can forward
data packets to the appropriate channel and corresponding network
interface.
[0041] Referring now to FIG. 10 through FIG. 13, WISE 20 can be
configured to support various combinations of wireless interfaces
as shown. FIG. 10 shows a dual mode 802.11a/b configuration, FIG.
11 shows a WLAN and WAN configuration, FIG. 12 shows a dual WLAN
and WAN configuration, and FIG. 13 shows a WLAN and dual WAN
configuration. For example, in FIG. 10, WISE 20 has one internal
interface 200 (a LAN host interface) and two external wireless
interfaces 202, 204, one of which is an 802.11a WLAN interface and
the other of which is an 802.11b WLAN interface. A similar
configuration is shown in FIG. 11, except that a cellular WAN
interface 206 is provided instead of the 801.11a interface 202
shown in FIG. 10. The configuration of FIG. 12 combines the
capabilities of the configurations of FIG. 10 and FIG. 11 by
employing all three types of wireless interfaces; namely, 802.11a,
802.11b and WAN interfaces. Lastly, the configuration of FIG. 13
employs an 802.11b interface and a GPRS interface 208 and a CDMA
interface 210. From the network IP address connection (OSI Layer 3)
point of view, there are three IP addresses for the mobile device
in the configurations shown in FIG. 10 and FIG. 11 and four IP
addresses for the mobile device in the configurations shown in FIG.
12 and FIG. 13. In other words, there is one IP address for the LAN
interface and a separate IP address for each of the wireless
interfaces.
[0042] For example, assume the configuration shown in FIG. 11 which
corresponds to the protocol stack shown in FIG. 2. The two external
interfaces provide gateway routing functions for the internal LAN
IP address of mobile device 18. Referring to FIG. 14, if the WLAN
interface 26 is the active interface, data packets from mobile
device 18 would be communicated from LAN interface 22 (IPO) to WLAN
14 through WLAN interface 26 (IP1). On the other hand, if the WAN
interface 28 is the active interface, data packets from mobile
device 18 would be communicated from LAN interface 22 (IPO) to WAN
12 through WAN interface 28 (IP2). It will be appreciated,
therefore, that the WISE 20 protocol stacks shown in FIG. 2 and
elsewhere are not limiting; the protocol stack would be expanded to
accommodate any particular number and/or type of wireless interface
to which mobile device 18 would be connected.
[0043] It will be appreciated, therefore, that WISE 20 provides a
seamless roaming capability to a mobile device. However, in
addition to seamless roaming, since battery life is an important
consideration with any mobile device WISE can provide power
management to shut down, or to place into standby, wireless
interfaces that are not being used. For example, referring again to
FIG. 14, if WLAN interface 26 is not the active interface, it can
be powered down. Note also that, when mobile device 18 is moving
farther way from, for example, WLAN 14, the signal quality for the
WLAN interface 26 may degrade. In that instance, WISE 20 can turn
on WAN interface 28 in preparation for roaming when the WLAN signal
is no longer usable.
[0044] While the invention has been described in terms of specific
types of wireless networks and wireless network interfaces, those
skilled in the art will appreciate the invention is not so limited
and that any wireless network and associated network interface can
be accommodated. It will further be appreciated that the invention
can be implemented in firmware and/or software using conventional
hardware design and programming techniques. Although the
description above contains many details, these should not be
construed as limiting the scope of the invention but as merely
providing illustrations of some of the presently preferred
embodiments of this invention. Therefore, it will be appreciated
that the scope of the present invention fully encompasses other
embodiments which may become obvious to those skilled in the art,
and that the scope of the present invention is accordingly to be
limited by nothing other than the appended claims, in which
reference to an element in the singular is not intended to mean
"one and only one" unless explicitly so stated, but rather "one or
more." All structural and functional equivalents to the elements of
the above-described preferred embodiment that are known to those of
ordinary skill in the art are expressly incorporated herein by
reference and are intended to be encompassed by the present claims.
Moreover, it is not necessary for a device or method to address
each and every problem sought to be solved by the present
invention, for it to be encompassed by the present claims.
Furthermore, no element, component, or method step in the present
disclosure is intended to be dedicated to the public regardless of
whether the element, component, or method step is explicitly
recited in the claims. No claim element herein is to be construed
under the provisions of 35 U.S.C. 112, sixth paragraph, unless the
element is expressly recited using the phrase "means for."
* * * * *